Design and In Vivo Evaluation of a Pogostemon cablin Nanoemulsion: Dose Determines the Balance between Anti-Inflammatory Efficacy and Mechanical Wound Integrity in a Novel Post-Burn Scar-Revision Model
22nd International Pharmaceutical Technology Symposium IPTS 2026, Ankara, Türkiye, 9 Eylül - 11 Ekim 2026, ss.74-75, (Tam Metin Bildiri)
- Yayın Türü: Bildiri / Tam Metin Bildiri
- Basıldığı Şehir: Ankara
- Basıldığı Ülke: Türkiye
- Sayfa Sayıları: ss.74-75
- Anadolu Üniversitesi Adresli: Evet
Özet
Introduction: Essential-oil nanoemulsions for wound healing are almost invariably tested on incisions in naive, unscarred skin, unlike post-burn scar revision surgery, where incisions adjoin previously injured tissue. Pogostemon cablin (patchouli) essential oil contains anti-inflammatory sesquiterpenes, yet its nanoemulsion has never been tested in this post-burn setting. This study evaluated the cytotoxicity and wound-healing activity of a P. cablin nanoemulsion (2.5%, 5%) in a novel fusiform-excision, primary-closure model created adjacent to a healed thermal scar [1], benchmarked against two established topical agents.
Material-Methods: P. cablin oil was hydrodistilled and characterized by GC-MS. Nanoemulsions (oleic acid oil phase; Cremophor® EL/Tween 20 surfactants; Transcutol® cosurfactant; S/CoS 2:1; 2.5%/5% P. cablin oil) were developed via pseudoternary phase diagrams/spontaneous emulsification. Cytocompatibility (MTT, L-929 fibroblasts) was assessed. Thirty-six female Wistar rats bearing a healed 21-day thermal scar underwent adjacent fusiform excision (primary closure; control, placebo, Contratubex®, Fito® 5%, P. cablin 2.5%/5%; n=5/group). At day 10, incision length, breaking strength, dehiscence, and tissue inflammatory/remodeling biomarkers (ELISA) were assessed.
Results and Discussion: GC-MS identified 28 constituents (98.56% of oil), led by patchouli alcohol, β- pinene and trans-nerolidol. Nanoemulsions showed droplet sizes 230–273 nm, near-neutral zeta potential, and skin-compatible pH (5.3–5.4); no formulation reduced L-929 viability below 80%. In vivo, incision length was unchanged (p = 0.102), whereas breaking strength differed (p = 0.042): Fito® was highest (8.42 ± 0.60 N); 2.5% P. cablin exceeded control/placebo (6.08 ± 0.39 N) with zero dehiscence, whereas 5% P. cablin was lowest (4.62 ± 1.12 N) with 40% dehiscence (vs. pooled others, p = 0.043). Tissue IL-6 differed (p = 0.006), suppressed dose-dependently, lowest at 5% (0.183 ± 0.026 vs. placebo 0.380 ± 0.028 pg/mg protein, p = 0.009), without changes in TNF-α, IL-1β or TGF-β2, indicating selective anti-inflammatory action [2]; VEGF was also lowest at 5% (p = 0.031). The concentration with the greatest anti-inflammatory effect coincided with the poorest mechanical outcome,a hormetic dose-response [3].
Conclusions: In this post-burn scar-revision model, P. cablin nanoemulsion exerted a selective, dose- dependent anti-inflammatory action, but only the 2.5% formulation preserved mechanical wound integrity, while 5% compromised it. These findings identify 2.5% P. cablin nanoemulsion as the mostpromising candidate, showing that anti-inflammatory efficacy alone is an insufficient criterion for optimizing wound-care formulations.
Acknowledgment: The authors acknowledge the approval of the animal protocol by the SABİDAM Local Ethics Committee for Animal Experiments (Approval No. 22.10.2025–10/11).
Keywords: Nanoemulsion, Pogostemon cablin, Post-burn scar revision, Topical drug delivery, Wound healing
References
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